This invention pertains to accordion type folding doors secured against vandalism and forcible entry.
A widely used and popular accordion type folding door comprises an assembly of vertically arranged panels placed side-by-side and suspended from a suitable track. The adjacent side edges of the panels are interconnected by sheet vinyl plastic hinges, the use of which is attended by two serious disadvantages:
In the first place, the vinyl hinges are easily cut by means of a knife or other sharp instrument, thereby vandalizing the door and providing openings into which crowbars or other tools may be inserted for the purpose of gaining entry.
Second, since the vinyl hinges are flexible and extend the entire length of the door, they impart a degree of flexibility and instability to the door assembly, rendering it unsuited for use in the protection of secure areas.
It is the general purpose of the present invention to provide an accordion type folding door assembly wherein the panel components are hinged to each other by means of strong, rigid, supplemental hinge members which cannot be cut with a knife and which staunchly resist attempts to separate the panels by destroying their hinging connections.
It is another important object of the present invention to provide an accordion type folding door assembly which is strong and rigid and which accordingly affords substantial protection to a space behind the door which is to be secured against entry.
A further object of the present invention is the provision of a secure-type accordion folding door which may be provided by the manufacturer as an alternate style of his product, without requiring the use of radically modified door components.
Still a further object of the present invention is the provision of an accordion type folding door which is of good appearance; easily assembled; easily installed; and, after installation, of long life substantially free from serious maintenance requirements.
Broadly stated, the folding door assembly of our invention, which accomplishes the foregoing and other objects, comprises a plurality of vertically arranged panels adapted to be suspended from a mounting track in vertical side-by-side arrangement.
Upper and lower primary hinges hinge together the upper and lower margins of each pair of panels. Supplemental hinging assemblies made of tough, durable components interconnect the panels in the spaces intermediate the primary hinges.
Each supplemental hinge assembly comprises a plurality of knuckles made of hard durable plastic or metal and tongue and groove or other means for attachment of the knuckles to the side margins of the adjacent panels in alternating arrangement, i.e. with alternate knuckles attached to the same panel.
A hinge pin made of steel or other stout material is received in the knuckles. It extends the entire distance between the pin hinges. In effect, it "floats" in its seated position, being unsecured directly to a structural member, but trapped between the primary hinges so that the hinge assembly cannot be inadvertently disassembled. The space between the panels thus is armored and rendered invulnerable to attack.